To turn off or not to turn off...

[Leinado]

I recently heard or read that it's better to leave your computer running rather that doing a shutdown when it's not in use.
Anyone know if this has any merrit, and if so why?

[soybean]

Ah, the age-old question ....    Turn it off, at least overnight, and save the energy.  It'll be obsolete long before any stress to metals from heating and cooling causes component failure. 

And, don't forget about power saving options such as Standby for the computer and setting the monitor to go into low-power mode after a certain time of no activity.

[beanhead07]

I agree with Soybean, either turn it off or put it on standby to save some power if it's not in use. Plus if you go for extended periods of time without restarting your computer it could cause problems. (I work in the IT department at my office and I can't tell you how many people come to me with "problems" and all I've had to do is restart their computer and it works fine again) but these people never shut down their computers, many never even log off. So save some energy and either shut it off or put it on standby.

[Panda25]

I heard on a tech show that if you're not going to be using your system for three hours or more you should turn it off.  It seems like a good idea to me and that's usually what I do.  (Plus turning it off every night like you suggest.)